Provide a shade release package for Dubbo with some common used libraries shaded.

[chickenlj]

As a middleware framework that works as a core dependency of many business projects, Dubbo relies on some other low-level libraries like Netty, which causes it easy to conflict if other middlewares depend on the same libraries but with different versions. To solve this, I think it's necessary for Dubbo to introduce a shade release package with those common dependencies shaded inside.

To achieve that, firstly, I think we should recognize all the third-party dependencies that are depended on by Dubbo and are easy to cause dependency conflicts.

[chaicho]

Assign the issue to me please.